Flame and spark arrester



Dec. 4, 1956 v c. LISCIANI 2,772,537

FLAME AND SPARK ARRESTER Filed Feb. 4, 1953 2 Sheets-Sheet l N n N vi Q fir/6712 27 1956 c. LISCIANI 2,772,537

FLAME AND SPARK ARRESTER Filed Feb. 4, 1953 2 Sheets-Sheet 2 50725222712 UzeLzlECc'aruL United States Patent FLAME AND SPARK ARRESTER Constantine Lisciaui, Chicago, Ill., assignor to The Protectoseal Company, Chicago, 111., a corporation of Illinois This invention relates to a flame and spark arrester and more particularly to a type of flame and spark arrester which is attached to the exhaust pipes of automotive vehicles such as trucks or industrial-type trucks, lift trucks, tow trucks, and the like, used for industrial purposes in factories and also for use with tractors of the type used for agricultural purposes, either in the field or for running various equipment close to or within barns or buildings where a fire hazard may occur because of the running of the engine, and automotive vehicles and tractors of this type equipped with this invention are equally adapted for use in the fields in combining or threshing or in cultivating where any glowing sparks may come in contact with dry vegetation or explosive mixtures, such as may come from the discharged chaff from the combining operation, which normally would constitute a fire h'aZard The invention also relates to a flame arrester or fire baflle construction which more particularly relates to devices adapted for mounting in vent openings, conduits, and the like, and in other devices for storing or conveying volatile and inflammable fluids in which the construction takes the form of a barrier, permitting the gases or fluids to flow therethrough, and at the same time extinguishing any flame or sparks resulting from the ignition of gases or fluids contained in or flowing into or out of the conduit or receptacle.

The invention is also capable of use with the exhaust pipes of auxiliary engines, such as are used for supplying power for driving the mechanism of devices, such as hay balers, cotton pickers, combines, potato diggers, and the like, where there is a possible chance of the flowing car bon particles starting a fire in the vegetation over which the various machines may travel.

A principal object of this invention, therefore, is to provide a flame and spark arrester and/ or exhaust arrester of this type to prevent the explosive pressures of industrial engines and the like, from discharging a flame which is liable to ignite any inflammable fluids over which the vehicle may pass.

Another object of the invention is to provide an exhaust arrester of this type, which is adapted for mounting either to an exhaust pipe positioned horizontally and mounted relatively close to the ground, or to provide the exhaust arrester of this type to exhaust pipes of farm tractors and the like, which extend vertically in the air above the tractor.

Another object of this invention is to provide a flame and spark arrester of this type, which is equally adapted for use with large motor trucks in which the exhaust is either discharged normally, horizontally to the ground and slightly above the ground, or vertically as in busses and vehicles and diesel-powered or gasoline-powered trucks.

Still another object of the invention is to provide a backfire arrester of this type, which is equally adapted for mounting on an exhaust pipe or the carburetor intake, to prevent back-fire from the engine to which the arrester is mounted from igniting inflammable fluids or explosive mixtures.

Patented Dec. 4, 1956 Another object of this invention is to provide a flame and spark arrester of this type, which may be readily dismantled and cleaned.

Still another object of the invention is to provide a back-fire arrester of this type suitable for mounting on one cylinder, two and three cylinder and four cylinder engines; also, on engines up to cubic inches in displacement.

Still another object of the invention is to provide a flame arrester of this type, which is readily disassembled for repair and replacement.

Another object of the invention is to provide a backfire arrester of general application of sufficient cooling capacity to reduce the temperature of the explosive flame below the ignition point of the ignition temperature of various inflammable fluids and explosive mixtures.

Another object of the invention is to provide a flame and spark arrester of general application, which reduces the temperature of any carbon particles below the ignition temperature of various inflammable fluids and explosive mixtures over which the vehicle to which the spark arrester is attached or the auxiliary engine, so that the flowing carbon particles are sufiiciently cooled and, if discharged from the spark arrester, will not cause ignition.

The spark phenomenon for which this invention is adapted to prevent is believed to have been fully described in a prior patent of Anschicks No. 1,960,043 granted May 22, 1934, and assigned to the Protectoseal Company of America, assignee of the present invention. The present invention, which is an improvement over the prior patent and is particularly adapted for the exhausts of internal combustion engines of the type set forth above, is also in the nature of an auxiliary attachment or shield which is placed on the exhaust outlet of an internal combustion engine. The spark arrester portion is so constructed that the advancing high velocity sparks through the exhaust pipe or from the muflier will all strike the shield and be extinguished by such contact. The ports provided by the corrugated plates and spacer plates in certain of the embodiments or by the tubular members in another of the embodiments form a devious path opened through the arrester and permit the pressure waves and flame-bearing gases to pass therethrough, and the length of these members are such as to quench any flames. The sparks generated back of the arrester strike against the walls of the passages and have their velocity slowed down sufliciently that they do not survive the pasage through the main body of the arrester. Any new sparks as may be generated in the narrow passages, for example, in one embodiment between the screen at one end and the screen at the other end of the arrester, do not require suflicient velocity or momentum to carry them through the flame extinguishing passages. An arrester of this type makes it impossible for live sparks to pass through the apertures provided for the escape of gases and pressure waves.

The proper functioning of flame arresters of this type require an enlargement at the end of the exhaust pipe or conduit to which it is attached, so that the arrester may be large enough to provide a series of apertured passages having a total cross-sectionalarea equal to or greater than the cross-sectional area of the most restricted portion of the exhaust pipe or conduit. An arrester thus constructed will not perceptibly slow up the velocity of the advancing pressure waves and ignited gases.

A still further object of the invention is the provision of a flame arrester for conduits and receptacles which permits flame-bearing gases and pressure waves resulting from an explosion within a muffler, conduit, or receptacle to quickly and readily pass through the arrester device and which at the same time extinguishes all sparks and flames generated by such explosion.

, Still another object of the invention is to provide a flame and spark extinguishing device of the kind described which effectively functions to permit the escape of gases and the distribution of pressure waves therethrough and at the same time prevents the passage of any sparks, however, great their velocity or small their dimen- SlOIlS.

Another object of the invention is to provide a device for preventing the passage of flame or sparks into or from any means for storing or conveying inflammable fluids, such device being especially rugged, simple iii construction, inexpensive to manufacture, and adapted for either large or small scale installations.

A still further object is to provide a device of the kind described which can be constructed to function in the presence of pressure waves, however great.

Other features of the invention include the use of 'U-'sh'aped tie rods or simple tie rods, depending upon whether the arrester construction comprises angular endretaining assemblies for assembling the sheet metal spacer plates and corrugated or dimpled forms of bafile plates, or whether the tubular members forming the arrester are assembled within a casing assembly of particular configuration and an end frame member complementally formed thereto.

In order to accomplish the various objects of the invention, a preferred form of flame and spark arrester and/ or exhaust arrester has been provided, which has a detachable connection for connecting to an exhaust pipe and in which the pipe adapter and flame arrester are the same for various size arresters, the capacity of the flame arrester being provided by changing the lengths of the housing and the corrugated and intermediate plates forming the flame and spark arrester portion, and the tie rods for assembling the casing assembly and the sheet metal corrugatedfins and arrester plates.

In another embodiment of the invention, the flame and spark arrester of this invention is provided by a series of sheet metal arrester plates which are suitably dimpled so that, when assembled, the plates are suitably spaced to provide a passage for the gases being cooled and suflicient turbulence to increase the cooling capacity.

Still another embodiment of the invention for accomplishing the above objects is-provided by assembling a series of assembled tubing of suitable heat conductivity, such as copper, brass, and aluminum, to eflectively cool the gases as they are discharged therethrough when assembled Within a casing assembly of particular geometrical configuration, such as for example, hexagonal in crossse c'tion', or the like, and in which the capacity of the arrester is determined by the length of the arrester and the cross-sectional area of the casing assembly.

Many other objects and advantages of the construction herein shown and described will be obvious to those skilled in the art from the disclosure herein given.

To this end my invention consists in the novel construction, arrangement and'combination of parts herein shown and described andmore particularly pointed out in the appended claims. I

In the drawings wherein like reference cate like or corresponding parts:

Fig. l is a longitudinal sectional view through the exhaust arrester, illustrating the casing assembly, baflle plates, pipe adapter, and clamp member for affixing the parts of the arrester together;

Fig. 2 is an end view or" the arrester, illustrating the discharge outlet thereof;

Fig. 3 is a view in end elevation, illustrating the inlet characters indiend of the arrester which is attached to an exhaust P p Fig. 4 is a partial plan view taken along line 4 1 of Fig. 1, partly in section, illustrating the construction of assembled with a hexagonal shaped casing assembly;

Fig. 9 is an end view of the exhaust arrester of Fig. 8, illustrating the discharge outlet thereof;

Fig. 10 is a view in elevation, illustrating the inlet end of the exhaust arrester of Fig. 8; and

Fig. 11 is a view in perspective of the hexagonal casing assembly of the embodiment of Fig. 8.

Referring more particularly to the embodiment illustrated in Figs. 1, 2, 3, and 4, there is illustrated an end of the exhaust pipe on 11 of an internal combustion engine to which the flame and spark arrester or exhaust arrester 12 is detachably aflixed. Although the exhaust arrester has been illustrated as being attached to a threaded end, it is within the scope of the invention that the exhaust arrester may be suitably flanged to be clamped to a comple'mentally formed flange on the exhaust pipe or clamped to the exhaust pipe or other conduit in any well-known manner, and this may also be in the form of an intermediate adapter coupling which is adapted at one end to mount the exhaust arrester, and at the other end is adapted to be secured to a conduit or exhaust pipe of an internal combustion engine. The flame and spark arrester 12 is provided with a pipe adapter 13 preferably formed of cast aluminum, which is threaded at 14 to receive the complementally formed threaded end of the exhaust pipe 11. The adapter has a divergent opening 15, which has oppositely formed ledges 16 within the peripheral flange 17. The peripheral flange 17 is complementally formed to a tubular casing 18, which in the embodiment shown in Fig. 2 is rectangular in cross-section, and is formed from similar halves 19 which have diagonally extending portions 20 which are seam-welded or spotweldcd to assemble the two halves into a unitary casing. The diagonally extending portions 20 extend from the outlet end of the casing to substantially the position shown in Fig. 4 in which they are spaced from the inlet end of the casing 13 to abut against a stop 21 of the peripheral flange 17, Figs. 2 and 4, to locate the tubular housing within the pipe adapter 13. Assembled within the tubular casing 18 are a series of alternately mounted corrugated baflle plates 22 and spacer plates 23 forming heat exchanger elements. The edges of the corrugated baflle plates 22 and spacer plates 23 rest on the oppositely positioned ledges 16, Fig. 1, and are prevented from being longitudinally detached from the casing 18 by end retainers 24.

The end retainers 24 comprise angular members 25, one leg of which abuts the ends of the corrugated baflle plates 22 and spacer plates 23, as illustrated in Fig. 2, and the other leg abuts a face at the upper end of the casing 18, Fig. 1. A locating guide 26 is welded or otherwise atfixed to the leg 25', Fig. l, of each of the end retainers 24, and a U-sh aped tie rod 27 extends through the lo'c'ating guides 26 of each of the end retainers 24 at the upper .end of the casing 18, and the free ends of the tie rod extend through openings in bosses 28, Figs. 1 and 4. Nuts .or other securing means 29, which are complementally threaded to receive the threaded ends 30 of the tie rod. secure the casing 18 and the corrugated baflle plates 22 and spacer-plates 23 assembled therein to the pipe adapter end retainers 24. With this construction, as the nuts 29 are tightened on the tie rod, the portions 31 thereof similarly abut the end retainers 24 to prevent the corrugated plates 22 and 23 from becoming disassembled from the casing 18 and, at the same time, secure the casing 18 in assembled relation to the pipe adapter 13. It is to be understood that it is Within the scope of the invention that the portions 31 of the tierod 27 may be welded or otherwise afiixed to the legs 25" and the use of locating guides 26 avoided.

As viewed in Figs. 1, 3, and 4, the pipe adapter 13 is provided with a hexagonal shaped portion 32 to receive a suitable wrench for assembling the pipe adapter on the threaded end of the combustible gas conduit or exhaust pipe 11.

Referring to Figs. 1 and 2, the baflle plates 22 are formed with corrugations in which the depth thereof is 0.108 and the pitch of the corrugations is A1". For use with one-cylinder engines, the length of the battle plates is preferably 6" with the width of the plates being 1%", and a sufficient number of alternate corrugated baflle plates 22 and spacer plates 23 are assembled that the thickness of the assembled plates is also 1%". The pipe size for the pipe adapter 13 for an exhaust arrester for a one-cylinder engine is 1''. For two-cylinder and three-cylinder engines, the pipe size of the adapter 13 is 1%" and the length of the bafiles is 7, and the baffle plates and the adapter 13 are such that, when assembled, the width and thickness of the assembled baffle plates 22 and 23 are 2%". For a four-cylinder engine, the pipe adapter is adapted to receive a 1 /2" pipe, and the lengths of the corrugated bafile plates 22 and spacer plates 23 is 8", and the width and thickness of the assembled plates 22 and 23, as illustrated in Figs. 2, is 2 /2. Although it is within the scope of the invention that the baffle plates may be assembled to any suitable size, depending upon the cross-sectional area of the exhaust pipe or conduit to which the arrester is assembled, the previous sizes have been found suitable for industrial engines of one, two, three, and four cylinder engines, and engines up to one hundred cubic inches in displacement. It is to be understood that it is within the scope of the invention that, if desired, one or more of the flame and spark arresters may be mounted in parallel on a suitable adapter wherever it is desired to increase the capacity of the flame and spark arrester for any increased horsepower or displacement of an engine to which the arrester is coupled.

While it is preferred to form the coupling 13 from cast aluminum and the corrugated baflles and spacer plates from sheet aluminum, it is within the scope of the invention that any suitable material may be used which has high heat conductivity for dissipating the heat of the combustible fluids discharged through the flame arrester, that the combustible gases are cooled down to a point where they are not dangerous and do not ignite or if they are ignited the flame is extinguished, and also that the temperature of any sparks formed is also reduced as they are discharged and before they come in contact with any inflammable material are cooled, so that they will not ignite any inflammable fluids over which the vehicle, which has an exhaust arrester of this type may pass or the sparks will not ignite any explosive mixtures such as one encounters with the use of industrial trucks and the like, or with agricultural tractors either within the barns or in the field.

Referring to Figs. 5 and 7, there are illustrated modified forms of baflle plates which are assembled within the tubular casing 18 in the same manner as the corrugated baffle plates and spacer plates are assembled. With the embodiment of Figs. 5, 6, and 7, however, only one form of plate 33 or 33 is necessary and the dimples 34 are formed in such a manner that by the reversal of the plate, 'the plates 33 or 33' are suitably spaced and none of the dimples 34 nest. For example, each of the plates 33 or 33 are assembled so that the sizes for one, two, three and four cylinder engines are substantially the same as disclosed above. An arrester plate 33 or 33 for a fourcylinder engine which is coupled to a 1% pipe, may have a length of 7 and a width of 2 The dimples 34a and 34b, referring to the modified plate 33' Fig. 7, are preferably spaced in from the longitudinal edges and the center lines for the rows of dimples of the plate are preferably spaced apart, and for this particular size there are fifteen spaces. The dimple 34a is spaced A" from the end and the dimple 34b is spaced /2 from the end, and similarly formed dimples a and b on the opposite end are reversed in position. The longitudinal spacing of the dimples beginning from the end of the plate 33' contiguous to the dimple 34b is A", A", A", A", four /2" spacings, two M4" spacings, one /2" spacing, two A" spacings, four /2 spacings, one spacing, and four A spacings. The smaller plates for the 1 pipe coupling and the 1% pipe coupling are similarly spaced and the blanks are respectively 5 in length and 1 wide, and 6 long and 2 ,5 wide. The blanks are formed from 0.25" thick aluminum sheets and the dimples are .150" in diameter and extend .05" above the thickness of the plate. With the arrangement as described for the largest size arrester and when the smaller size plates are similarly formed, it is possible to reverse the plates end for end so that none of the dimples nest and the plates are suitably spaced to provide exit passages for the combustible and inflammable gases discharged therethrough. The dimples are so arranged that when viewed from the inlet end of the arrester, they overlap to prevent any sparks from traveling through the passageways formed, and the sparks would at some time impinge against a dimple. The dimples in addition to baffling the path of the combustible gases cause suflicient turbulence to increase the rate of heat transfer to extinguish any flame and also to effectively cool or extinguish any sparks formed and which might be discharged from the arrester.

In order to dismantle the flame and spark arrester or exhaust arrester of the embodiments of Figs. 1 through 4 and that of Figs. 5, 6, and 7 for cleaning or replacement of parts for repair, it is only necessary to remove the nuts 29 from the U-shaped tie rod 27 and detach the tie rod from the bosses 28. Since the locating guides 26 engage the legs of the U-shaped tie rod 27 and there is suflicient resilience in the legs of the tie rod, when the tie rod is removed, the end retainers 24 Will, for the most part, be retained on the tie rod. It is also possible to detach the tie rod separably from the retainers or, in some instances, one may detach the tie rod and the casing together from the pipe adapter 13. If the corrugated bafile plates 22 and spacer plates 23 have become stuck together because of the carbon deposits, they may be detached by tapping them on the outer ends or they may be separably detached. After the baffle plates 22 and 23 have been removed, they may be wire-brushed clean to remove any carbon deposits. If any of the plates have become damaged in use, they may be readily replaced when assembled. In assembling the arrester, the parts are assembled in the reverse order and the casing, and the plates clamped in place by securing the nuts 29, as illustrated in Fig. 1 to the free ends of the tie rod 27. v

In the embodiment of Figs. 5, 6, and 7 in which only one plate 33 or 33 is used instead of alternate corrugated battle plates 22 and spacer plates 23, the arrester is dismantled in the same manner and, when dismantled, the plates 33 or 33 may also be brushed clean and replaced in the event of any wear or corrosion. In reassembling, the plates are alternately reversed end for end so that the passages are formed between the plates spaced by the dimples 34.

Referring to Figs. 8, 9, 10, and 11, there is illustrated another embodiment of an exhaust arrester 12' of my invention in which the casing 18 is hexagonal in shape removed from the pipe adapter.

' the'operation repeated. I Here is preferred because once the plates are disassembled 7 instead of rectangular, as illustrated in Fig. 2. The passages of this embodiment for cooling the exhaust gases or inflammable fluids discharged through the flame and spark arrester are formed by tubes 35 nested within the hexagonal casing 18. A pipe arrester 13 similarly formed to the pipe adapter 13 of the embodiment of Fig. l is threaded to receive a complementally formed threaded end '11 of an exhaust pipe or combustible gas conduit to which the exhaust arrester is adapted to be assembled. The threaded portion 14 diverges outwardly to provide a divergent opening 15' which is provided with a ledge 16 on which is seated the hexagonal shaped casing 18'. The tubular casing 18' is formed from halves 19' with diametrically extending portions 20', as illustrated in Fig. 11. The halves 19' are affixed together to form the hexagonal tubular casing 18 by seam-welding, spot-welding or otherwise afiixing the port-ions 20 together. The portions 20 are recessed back from the ends of the casing to permit assembly of the casing within the complementally formed hexagonal chamber 36 in the pipe adapter 13, and also in a similarly formed chamber 37 in the cast aluminum end retainer 38. The retainer 38 is formed with a hexagonal or suitably shaped opening 39 for the discharge of the gases through the arrester.

In assembling the parts of the arrester, a hexagonal shaped screen 40 is first assembled within the recess 36 after which the tubular casing 18 is assembled in position. Sufficient aluminum tubes 35 are nested within the hexagonal casing to completely fill it, after which another screen 40 is assembled over the tubes. The retainer 38 is then assembled over the end of the casing 18 and the screen 40, as illustrated in Figs. 8 and 9. Tie rods 41 are then asesmbled through holes in the bosses 42 and the threaded ends 43 of each of the tie rods are threaded into complementally threaded openings in bosses 44 formed on the pipe adapter 13 with the openings in the bosses 42 and 44 in alignment. The tie rods 41 may be threaded at each end, as shown in Fig. 8, and nuts 29 secured thereto on the outer ends of the tie rods, or it is also within the scope of the invention, that elongated bolts may be used. However, for simplicity in manufacture, it is preferable to use tie rods threaded on each end to receive the nuts 29 so that in assembly it is immaterial which end of the tie rod is assembled first in position. Upon securing the nuts 29 firmly in position against the face of the end retainer 38, the hexagonal casing 18', the screens 40, and the tubes 35 are firmly afiixed to the pipe adapter 13.

In order to disassemble the flame and spark arrester for cleaning and replacement of parts, it is only necessary to detach the nuts 2, after which the end retainer 38 is removed, whereupon the casing may be detached from the pipe adapter 13', and the screens 40 may also be removed. If the tubes, because of carbon deposits and corrosion, are stuck together, they may be readily detached by tapping one end of the tubes, whereupon they may be readily detached. After the outer and inner surfaces of the tubes have been carefully brushed clean, and the screens 40 cleaned as well as the interior of tube 18, the tubes may be reassembled within the casing and, if any of the tubes have been destroyed or damaged, they may be readily replaced as well as screens 40, if necessary. The casing 18' and the assembled tubes and screens are reassembled, as shown in Fig. 8 and the end retainer 38 assembled on the outer end of the casing and over the tie rods 41, if they have not been removed, and the nuts 29 replaced and secured in position.

The embodiments of Figs. 1 through 7 may also be cleaned by pushing each of the plates, one at a time, approximately half-way out of the end of the cartridge formed by the casing 12 and the plates after it has been Substantially one-half of each plate is individually brushed and then returned within the cartridge. The cartridge is then reversed and In most instances, this proceit is very difl ieult toreassemble. Similarly, the outer surface of the tubes 35 of the embodiment of Figs. 8 through 11 may be cleaned in this manner.

In either the embodiments of Fig. 1 and Fig. 8-, if it is desired, the entire arrester assembly may be detached from the threaded end of the conduit by unscrewing the arrester by applying a wrench to the hexagonal portion 32 of the pipe adapter 13, Figs. 3 and 10, after which the arrester may be disassembled, cleaned, and any parts replaced as described above.

In the embodiment, as illustrated in Fig. 1, it is preferred to form the spacer plates 23 from twenty-four gage (.020") aluminum sheet material and, likewise, the corrugated bafiie plates 22. The aluminum sheet material from which the dimpled arrester plates 33 or 33' are formed in the embodiment of Figs. 5, 6, and 7, is preferably formed from .025" thick aluminum sheet. The aluminum tubing 35 for the embodiment of Fig. 8 is preferably formed from aluminum tubing A 0. D., with a wall thickness of .020. The cross-sectional area of each of the embodiments is substantially twice that of the combustible gas conduit to which it is attached to prevent'excess back pressure for the gases discharged. The casing assemblies 18 and 18' are preferably formed from twenty gage terne plate, and the pipe coupling for each of the embodiments is preferably formed from cast aluminum, and the end retainer 37 of the embodiment Fig. 8 is also formed from cast aluminum. The nuts and tie rods are preferably formed from steel and plated.

Although the preferred materials and sizes have been disclosed, it is to be understood that it is within the scope of the invention that any suitable material having suitable heat conductivity, such as copper and brass, may be used, and the material used obviously depends upon theservice requirements.

Referring to the embodiment of Pig. 8, the width across the flats of the hexagonal casing for an arrester for a one-cylinder engine or one inch conduit is 1 /2" and the length is 6". For a two-cylinder and threecylinder engine and for a 1%" diameter exhaust pipe, the width across the flats of the hexagonal casing is 2 7 and the length 7". For a four-cylinder engine and for use with a 1 /2" exhaust conduit, the width across the flats of the hexagonal casing is 2 /2." and the length 8".

In each of the embodiments, the gases and pressure waves are free to be discharged through the arrester and deviate only slightly or not at all retarded thereby, since the total area of the apertures formed by the corrugated baflie plates 22 and spacer plates 23 and by the dimpled plates 33 in the embodiment of Figs. 5, 6, and 7 and also by the nesting of the tubes 35 in the embodiment of Fig. 8, is equal to or greater than cross-sectional area of the conduit to which the arrester is attached. Any high velocity sparks accompanying the pressure waves and ignited gases, although substantially following a straight path, may impinge on the faces of the passages formed in each 'of the embodiments and cooled thereby to become extinguished or are sufliciently cooled below the ignition temperature to become extinguished as they pass through the arrester passages by the cooling effect of the enlarged cooling surface of the nested baflie plates or tubes. Also, any new sparks, which may be generated within the passages of the arrester, are also sufliciently cooled before being discharged from the arrester as to prevent any damage. Also, any new sparks generated in the restricted spaces formed by the plates and the tubes of the various embodiments will not gain sufiicient momentum to be impelled or projected through the outlet end of the arrester. However, as illustrated in the embodiment of Fig. 8, if desired, a suitable screen or baflie may be additionally employed.

Thus, it will be seen that I have provided a combination flame arrester and spark extinguisher or exhaust arrester particularly adapted for internal combustion enginesof the type used with lift trucks, tow trucks, and the like, within factories, or upon farm tractors used in the fields or in barns which serve as a barrier to flames and sparks of all sizes, and permits the dissipation of gases and pressure waves resulting from explosions in a relatively confined space. It is also evident that there has been provided an arrester of this type which may be used with equal efliciency as a flame or spark arrester when mounted on an exhaust pipe of an internal combustion engine, extended either in a vertical position above the tractor or in a horizontal position on the tow truck or the like vehicle. It is also evident that an arrester of this type is equally suitable for large trucks, tractor trucks, passenger vehicles and the like, which may have to travel through areas which are hazardous because of inflammable materials and fluids or explosive mixtures over which or through which the vehicle is driven and sparks or flames from the exhaust pipe of the vehicle may ignite.

Having thus described my invention, it is obvious that various immaterial modifications may be made in the same without departing from the spirit of my invention; hence, I do not wish to be understood as limiting myself to the exact form, construction, arrangement and combination of parts herein shown and described or uses mentioned.

What I claim as new and desire to secure by Letters Patent is:

1. As an article of manufacture, an elongated polygonal-shaped tubular casing for a flame arrester comprising an adapter for detachably mounting the flame arrester on a combustible gas conduit at one end and for detachably mounting retainer means for the polygonal-shaped tubular casing on the opposite end, said polygonal-shaped tubular casing complementally formed to the adapter, said polygonal-shaped tubular casing comprising detachable and flanged symmetrical halves about the diagonal through the cross-section of the polygonal-shaped tubular casing at right angles to the longitudinal axis of the polygonal-shaped tubular casing, said flanged symmetrical halves assembled with the flanges thereof in abutting relationship and said polygonal-shaped tubular casing extending longitudinally to a predetermined length greater than the smallest cross-sectional dimension of the poly onal-shaped tubular casing, said polygonal-shaped tubular casing adapted to receive heat exchange members forming a plurality of longitudinally extending passageways in heat exchange relationship with respect to the combustible gas to be discharged therethrough, and said flanges of said symmetrical flanged halves forming the tubular casing being intermediate the ends of said tubular casing and less than the length of the tubular casing.

2. A flame arrester for a combustible gas conduit, comprising an adapter for detachably mounting the arrester to the conduit, said adapter formed with a rectangularshaped chamber providing an enlargement of the conduit, an elongated rectangular-shaped tubular casing detachably mounted upon the adapter, said rectangular-shaped tubular casing complementally formed to the adapter, said rectangular-shaped casing comprising detachable and flanged symmetrical halves about the diagonal through the cross-section of the rectangular-shaped tubular casing at right angles to the longitudinal axis of the rectangularshaped tubular casing, said flanged symmetrical halves assembled with the flanges thereof in abutting relationship, said rectangular-shaped tubular casing formed with a plurality of longitudinally extending passageways, a plurality of alternate rectangular-shaped corrugated baflle plates and similarly formed rectangular flat spacer plates providing said plurality of longitudinally extending passageways, extending substantially the length of said casing, said cross-sectional area of said passageways being substantially twice the cross-sectional area of the combustible gas conduit to which the flame arrester is mounted, whereby any ignited combustible gas discharged through the flame arrester is extinguished and any sparks formed as the combustible gases are discharged are cooled and extinguished.

3. A flame and spark arrester for an internal combustion engine comprising an adapter for detachably mounting the arrester to an exhaust pipe of the internal combustion engine, a detachable elongated and rectangularshaped tubular casing aflixed to the adapter, said rectangular-shaped tubular casing complementally formed to the adapter, said rectangular-shaped tubular casing comprising detachable and flanged symmetrical halves about the diagonal through the cross-section of the casing at right angles to the longitudinal axis of the rectangular-shaped tubular casing, said flanged symmetrical halves assembled with the flanges thereof in abutting relationship, said tubular casing formed for detachably mounting heat exchanger elements, said heat exchanger elements comprising a plurality of alternate rectangular-shaped corrugated baflie plates and similarly formed rectangular flat spacer plates and said corrugated bafiie plates and rectangular flat spacer plates extending substantially the full length of said tubular casing, a retainer construction complementally formed to the casing to retain the heat exchanger elements within the casing, and securing means for detachably afiixing the retainer construction to the casing of the adapter.

4. A flame and spark arrester for an internal combustion engine comprising an adapter for detachably mounting the arrester to an exhaust pipe of the internal combustion engine, a detachable, elongated and rectangularshaped tubular casing aflixed to the adapter, said rectangular-shaped tubular casing complementally formed to the adapter, said rectangular-shaped tubular casing comprising detachable and flanged symmetrical halves about the diagonal through the cross-section of the casing at right angles to the longitudinal axis of the rectangularshaped tubular casing, said flanged symmetrical halves assembled with the flanges thereof in abutting relationship, retainer means complementally formed to the casing, a plurality of alternate rectangular-shaped corrugated bafile plates and similarly formed rectangular flat spacer plates operatively mounted Within the rectangularshaped tubular casing providing a plurality of longitudinally extending passageways extending substantially the length of the tubular casing, said rectangular-shaped tubular casing being substantially square in cross-section, said adapter and retainer means complementally formed to the rectangular-shaped tubular housing, and U-shaped securing means for detachably aflixing the rectangularshaped tubular casing to the adapter, the U-shaped securing means extending through complementally formed and oppositely spaced openings in the retaining means and the adapter.

References Cited in the file of this patent UNITED STATES PATENTS 555,297 Anderson Feb. 25, 1896 603,378 Hagemann et a1. May 3, 1898 1,681,698 Brooks Aug. 21, 1928 1,826,487 Wiggins Oct. 6, 1931 1,839,655 Dobbins Jan. 5, 1932 1,887,305 Helmore et al. Nov. 8, 1932 2,277,294 Brooks Mar. 24, 1942 2,651,322 Hendry Sept. 8, 1953 

